Scholars have been debating what constitutes “the Southwest” for decades. Thirty years ago, geographer D. W. Meinig began his landmark study Southwest: Three Peoples in Geographical Change, 1600–1970 by stating: “The Southwest is a distinct place to the American mind but a somewhat blurred place on American maps.” For Meinig, the crucial determining factor in constituting the geographical parameters of his own study was the coincidence of Native American and Mexican American settlement patterns in Arizona, New Mexico and around El Paso, Texas. The watersheds of the Gila River in Arizona and the Rio Grande in New Mexico provide the focus of his study of the historical interaction of Indians, Mexican Americans and Anglos through the successive periods of Spanish colonialism, Mexican independence and American rule. The historical geographer Richard Francaviglia has challenged the relatively narrow focus of Meinig's study by calling for a more expansive consideration of the Greater Southwest, which, in addition to the core of Arizona and New Mexico, also includes parts of Colorado, Utah, Texas and the northern states of Mexico. He rationalizes, “The southwestern quadrant of North America is, above all, characterized by phenomenal physical and cultural diversity that regionalization tends to abstract or simplify. The more one tries to reduce this complexity, the smaller the Southwest becomes on one's mental map.”2